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Mercury pendulum tubes


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I have a french four glass clock that has a mercury pendulum, I have noticed that the tubes where placed upside down I have placed them the right way up, how long does it take for the mercury to run to the bottom of the tubes because its not exactly free running stuff, I think it would be pointless trying to regulate the clock until it has is this correct ?

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Are you sure its a real mercury pendulum?

I've heard of cheaper clocks having fake mercury pendulums, could it be the pendulum was taken apart and put together incorrectly with the pretend mercury parts upside down?

The whole point of mercury is it is liquid and flows freely as Old Hippy says

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From what I see the clock is a genuine French Four Glass. Mercury can solidify only with extreme cold. Myself I have never come across these what I will call dummy type pendulums. It would probably be best to replace them. I don’t think here in the UK you can post mercury.

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1 hour ago, Tmuir said:

Are you sure its a real mercury pendulum?

I've heard of cheaper clocks having fake mercury pendulums, could it be the pendulum was taken apart and put together incorrectly with the pretend mercury parts upside down?

The whole point of mercury is it is liquid and flows freely as Old Hippy says

No I'm sure these are mercury its a very good quality french clock I dont think they are replacement mercury vials I may put them in some slightly warm water and see if that helps.

 

6 minutes ago, oldhippy said:

From what I see the clock is a genuine French Four Glass. Mercury can solidify only with extreme cold. Myself I have never come across these what I will call dummy type pendulums. It would probably be best to replace them. I don’t think here in the UK you can post mercury.

Thats the problem they only seem to be readily available in America and I think it would be illegal to try and import mercury via the postal service into England and they are also very expensive.

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  • 8 months later...

From the photos, those tubes look a little more sophisticated than simple glass phials containing mercury. It looks like they may be double-walled tubes, where the mercury sits in the annular space between inner and outer glass walls. That would explain the strange behaviour of the mercury. 

Can you get a really good close-up shot of one of the tubes looking at the top of the mercury? Try to see if there’s a visible meniscus in a ring. 

This is only a hunch as I’ve never handled one of these myself!

Phil G4SPZ

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  • 7 months later...
On 6/18/2019 at 6:46 PM, wls1971 said:

I have a french four glass clock that has a mercury pendulum, I have noticed that the tubes where placed upside down I have placed them the right way up, how long does it take for the mercury to run to the bottom of the tubes because its not exactly free running stuff, I think it would be pointless trying to regulate the clock until it has is this correct ?

I know this is an old post. As a dentist, I've worked with mercury a lot. Mercury does not solidify at room temperature.

And when it melts in hot water, that sounds like the sister element of mercury, Gallium. 

Just out of curiosity, after the vials cooled, did the "mercury" remain a liquid or did it resolidify?

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The odd behaviour suggests some other alloy, or the mercury is somehow sticking to the glass.

There are a number of low temperature alloys including Woods metal that might work as pendulum, since they contain heavy metals like bismuth and lead, and which become liquid at less than the boiling point of water.

https://en.wikipedia.org/wiki/Wood's_metal

Mercury amalgams are very odd.

https://www.youtube.com/watch?v=2JW8YGTdTjA

 

.. and then there is Gallium

 

 

Edited by AndyHull
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24 minutes ago, HectorLooi said:

Would you believe Gallium was proposed as a safer alternative to mercury amalgam fillings for teeth!

I guess it depends on how you define "safe". Not particularly safe if you drop one of your gallium fillings on the floor of a 747, half way across the Atlantic, but then again I think mercury is banned on flights for a very similar reason. 

The interesting thing about gallium is how little of it you need to completely destroy the integrity of aluminium.

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